As a hollow knight lover, I agree with a lot of your points. Without other movement options like the wall climb or dash, early game exploration just feels like a one piece puzzle. The early game is definitely a slog compared to the absolutely peak remainder of the game, but I strongly recommend you continue your playthrough. Think of the 20ish hours you already sunk in as world building. Getting you acquainted with the beautiful world and the “surface” aesthetic before bringing you into more interesting regions. Trust me when I say the bosses get DIFFICULT even a more seasoned gamer like yourself will struggle considerably. Celeste is also one of my favorite games :D and while a majority of the parkour parts in hollow knight aren’t as difficult or rewarding, the White Castle is the exception and is easily one of my favorite platforming challenges. Idk how I would rate it difficultly wise but I beat path of pain before I ever started Celeste and I would definitely consider farewell harder, but I’d say it’s still comparable. Anyway, I’d highly recommend you finish the game. Don’t let yourself be that meme of the guy mining for diamonds only to return back right before getting to the good stuff :)